500 research outputs found
Classic and spatial shift-share analysis of state-level employment change in Brazil
This paper combines classic and spatial shift-share decompositions of 1981 to 2006 employment change across the 27 states of Brazil. The classic shift-share method shows higher employment growth rates for underdeveloped regions that are due to an advantageous industry-mix and also due to additional job creation, commonly referred to as the competitive effect. Alternative decompositions proposed in the literature do not change this broad conclusion. Further examination employing exploratory spatial data analysis (ESDA) shows spatial correlation of both the industry-mix and the competitive effects. Considering that until the 1960s economic activities were more concentrated in southern regions of Brazil than they are nowadays, these results support beta convergence theories but also find evidence of agglomeration effects. Additionally, a very simple spatial decomposition is proposed that accounts for the spatially-weighted growth of surrounding states. Favourable growth in northern and centre-western states is basically associated with those states’ strengths in potential spatial spillover effect and in spatial competitive effect
Time-Consistent and Market-Consistent Evaluations
We consider evaluation methods for payoffs with an inherent financial risk as
encountered for instance for portfolios held by pension funds and insurance
companies. Pricing such payoffs in a way consistent to market prices typically
involves combining actuarial techniques with methods from mathematical finance.
We propose to extend standard actuarial principles by a new market-consistent
evaluation procedure which we call `two step market evaluation.' This procedure
preserves the structure of standard evaluation techniques and has many other
appealing properties. We give a complete axiomatic characterization for two
step market evaluations. We show further that in a dynamic setting with a
continuous stock prices process every evaluation which is time-consistent and
market-consistent is a two step market evaluation. We also give
characterization results and examples in terms of g-expectations in a
Brownian-Poisson setting
Stock liquidity and SMEs’ likelihood of bankruptcy:evidence from the US market
We study the association between the stock liquidity of SMEs in the US and their likelihood of bankruptcy, using a dataset that comprises information on 5075 firms over the time period from 1984 to 2013 using the hazard model of Campbell et al. (2008). We find that less liquid stocks are associated with higher probability of bankruptcy, although there is substantial heterogeneity across industries regarding the predictive power of the liquidity measure on the likelihood of bankruptcy. Furthermore, the exchange where the SMEs are listed also affects the likelihood of bankruptcy. Classification performance tests conclude that adding a liquidity measure variable to the Campbell et al. (2008) model improves its predictive power
Oral rehydration versus intravenous therapy for treating dehydration due to gastroenteritis in children: a meta-analysis of randomised controlled trials
BACKGROUND: Despite treatment recommendations from various organizations, oral rehydration therapy (ORT) continues to be underused, particularly by physicians in high-income countries. We conducted a systematic review of randomised controlled trials (RCTs) to compare ORT and intravenous therapy (IVT) for the treatment of dehydration secondary to acute gastroenteritis in children. METHODS: RCTs were identified through MEDLINE, EMBASE, CENTRAL, authors and references of included trials, pharmaceutical companies, and relevant organizations. Screening and inclusion were performed independently by two reviewers in order to identify randomised or quasi-randomised controlled trials comparing ORT and IVT in children with acute diarrhea and dehydration. Two reviewers independently assessed study quality using the Jadad scale and allocation concealment. Data were extracted by one reviewer and checked by a second. The primary outcome measure was failure of rehydration. We analyzed data using standard meta-analytic techniques. RESULTS: The quality of the 14 included trials ranged from 0 to 3 (Jadad score); allocation concealment was unclear in all but one study. Using a random effects model, there was no significant difference in treatment failures (risk difference [RD] 3%; 95% confidence intervals [CI]: 0, 6). The Mantel-Haenzsel fixed effects model gave a significant difference between treatment groups (RD 4%; 95% CI: 2, 5) favoring IVT. Based on the four studies that reported deaths, there were six in the IVT groups and two in ORT. There were no significant differences in total fluid intake at six and 24 hours, weight gain, duration of diarrhea, or hypo/hypernatremia. Length of stay was significantly shorter for the ORT group (weighted mean difference [WMD] -1.2 days; 95% CI: -2.4,-0.02). Phlebitis occurred significantly more often with IVT (number needed to treat [NNT] 33; 95% CI: 25,100); paralytic ileus occurred more often with ORT (NNT 33; 95% CI: 20,100). These results may not be generalizable to children with persistent vomiting. CONCLUSION: There were no clinically important differences between ORT and IVT in terms of efficacy and safety. For every 25 children (95% CI: 20, 50) treated with ORT, one would fail and require IVT. The results support existing practice guidelines recommending ORT as the first course of treatment in appropriate children with dehydration secondary to gastroenteritis
Some physiotherapy treatments may relieve menstrual pain in women with primary dysmenorrhea: a systematic review
Question: In women with primary dysmenorrhoea, what is the effect of physiotherapeutic interventions compared to control (either no treatment or placebo/sham) on pain and quality of life? Design: Systematic review of randomised trials with meta-analysis. Participants: Women with primary dysmenorrhea. Intervention: Any form of physiotherapy treatment. Outcome measures: The primary outcome was menstrual pain intensity and the secondary outcome was quality of life. Results: The search yielded 222 citations. Of these, 11 were eligible randomised trials and were included in the review. Meta-analysis revealed statistically significant reductions in pain severity on a 0–10 scale from acupuncture (weighted mean difference 2.3, 95% CI 1.6 to 2.9) and acupressure (weighted mean difference 1.4, 95% CI 0.8 to 1.9), when compared to a control group receiving no treatment. However, these are likely to be placebo effects because when the control groups in acupuncture/acupressure trials received a sham instead of no treatment, pain severity did not significantly differ between the groups. Significant reductions in pain intensity on a 0–10 scale were noted in individual trials of heat (by 1.8, 95% CI 0.9 to 2.7), transcutaneous electrical nerve stimulation (2.3, 95% CI 0.03 to 4.2), and yoga (3.2, 95% CI 2.2 to 4.2). Meta-analysis of two trials of spinal manipulation showed no significant reduction in pain. None of the included studies measured quality of life. Conclusion: Physiotherapists could consider using heat, transcutaneous electrical nerve stimulation, and yoga in the management of primary dysmenorrhea. While benefits were also identified for acupuncture and acupressure in no-treatment controlled trials, the absence of significant effects in sham-controlled trials suggests these effects are mainly attributable to placebo effects
Assessing Interaction Networks with Applications to Catastrophe Dynamics and Disaster Management
In this paper we present a versatile method for the investigation of
interaction networks and show how to use it to assess effects of indirect
interactions and feedback loops. The method allows to evaluate the impact of
optimization measures or failures on the system. Here, we will apply it to the
investigation of catastrophes, in particular to the temporal development of
disasters (catastrophe dynamics). The mathematical methods are related to the
master equation, which allows the application of well-known solution methods.
We will also indicate connections of disaster management with excitable media
and supply networks. This facilitates to study the effects of measures taken by
the emergency management or the local operation units. With a fictious, but
more or less realistic example of a spreading epidemic disease or a wave of
influenza, we illustrate how this method can, in principle, provide decision
support to the emergency management during such a disaster. Similar
considerations may help to assess measures to fight the SARS epidemics,
although immunization is presently not possible
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Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework
Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays.
Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF.
Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge).
Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies
The ocean sampling day consortium
Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits
Is standard breast-conserving therapy (BCT) in elderly breast cancer patients justified? A prospective measurement of acute toxicity according CTC-classification
<p>Abstract</p> <p>Background</p> <p>Breast conserving therapy (BCT) is an accepted treatment for early-stage breast cancer. This study aimed to measure prospectively acute radiation-related toxicity and to create a comprehensive data base for long-term temporal analyses of 3D conformal adjuvant radiotherapy. The specific aspect of age has been neglected by traditional research. Therefore, the impact of age on acute BCT toxicity should be also specifically adressed.</p> <p>Methods</p> <p>Toxicity was measured in 109 patients at initiation (t1), during radiotherapy (t2-t7), and 6 weeks after treatment completion (t8) using a new topographic module. Organ systems were recorded in 15 scales and scored according to symptom intensity (grade 0-5) based on CTC (Common Toxicity Criteria) -classification. Radiotherapy was virtually CT-based planned and applied with 6-MeV-photons. Mean total dose was 60.1 Gy. Patients were stratified by age in 3 Groups: <50, 50-60, and >60 years.</p> <p>Results</p> <p>Registered toxicity was generally low. Mean overall-grade climbed from 0.29-0.40 (t1-t7), and dropped to 0.23 (t8). Univariate analyses revealed slightly higher toxicity in older (> 60 years) versus young patients (< 50 years) in 2 scales only: breast-symmetry (p = 0.033), and arm function (p = 0.007). However, in the scale "appetite" toxicity was higher in younger (< 50 years) versus older (> 60 years) patients (p = 0.039). Toxicity differences in all other scales were not significant. Between older (> 60 years) and midaged patients (50-60 years) no significant differences in toxicity were found. This was also true for the comparison between young (< 50 years) versus midaged patient groups (50-60 years).</p> <p>Conclusion</p> <p>The treatment concept of BCT for breast cancer is generally well tolerated. The toxicity-measurement with the new topographic module is feasible. Not modified standard treatment for BC should be performed in elderly women.</p
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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